Choke regulator



Aug. 7, 1934.

T. N. COFFELDER CHOKE REGULATOR Filed Nov. 29, 1929 INVENTOR PatentedAug. 7', 1934 UNITED stares.

PATENT mm This invention relates to improvements in car-- bureters for ,intemal combustion engines, more particularly to means for automatically regulating the choke valveof a carbureter in accordance with the operating condition of the engine to which it is attached.

. It is among the objects of this invention to provide means for automatically regulating the choke of carbureters in accordance with the operating requirements of' the combustion engine and whichshall be adapted to maintain a full choke on the carbureter in starting the engine or when the engine is dead and automatically open the choke valve when the engine is cranked and in operation.

Another object of the invention is to provide.

means fonregulating the speed of opening and closing the choke valve in accordance with atmosnate like parts and in which Fig. 1 is a side elevational view of an internal combustion engine embodying the principles of this invention; Fig. 2, a detail view of a portion of the carbureter of Fig. 1 illustrating the choke valve and the automatic valve'regulating mechanism; Fig. 3, a diagrammatic view of the invention embodying a holding mechanism; and Fig. 4, a side elevational view of a carbureter and choke regulator.

In the drawing 1 designates a cylindrical block of an internal combustion engine; 2 the head; 3 the exhaust manifold; 4 the intake manifold to 5 which a carbureter generally designated at 5 is connected by the flange 6. v

Carbureter 5. is provided with the usual pipe line connection 7 leading to a gas tank, a valve control lever 8 connected to the operating mechanism and the air intake 9 having the usual form of butterfly valve or choke 10 pivotally mounted thereon.

It'is the object of the butterfly valve to regulate the amount of air employed in the fuel mixture passing to the intake manifold 4 from which it is distributed to the various combustion chambers of the engine. In cranking an engine it is desired to utilize a very-rich mixture of gaseous fuel and accordingly thebutterfly valve 10 is regulated to choke ofl the air intake 9 until cranking is effected, when the butterfly valve 10 is immediately opened to permit the ingress of an adequate'supply of airto the mixing chamber of the carbureter 1. In accordance with the present invention, the butterfly valve 10 is automatically regulated to choke oil the air supply in cranking. 1

the engine d open the butterfly valve after cranking by means of the following mechanismt.

A suction device consisting of a cylinder 11 is connected through a line 12 to the intake manifold and is provided' with a piston member 13 operatively mounted therein, this piston being movable in a manner hereinafter explained. The butterfly valve 10 is provided with the usual lever arm 14 which, in the present instance, is biased by a coil spring 15 to maintain the position where the valve 10 is vertically disposed which is the full choke position of the carbureter, and lever 14 is connected by a link 16 to the end of the piston rod of piston 13.

In operation, the suction device functions to maintain the 'valve 10 in the full chokeposition by action of the spring 15 as long as no suction is available in the intakemanifold 4, this being during the idle period of the internal combustion engine. The full choke position is maintained during the cranking of the engine until combustion. is effected and the engine is cranked. The operation of the piston member in the internal combustion engine creates suction in the intake manifold .4 and alsoin the line 12 connecting the choke operating cylinder 11 and when the suction is created in such manner the piston 13 will be drawn in the direction of the suction line 12, pulling lever 14 away from. the biased position of as spring 15 and subjecting the valve 10 to angular I movement whereby the passage of the intake pipe line 9 is open. During the entire operation of the engine the choke valve 10 is maintained in" an open position and when the engine is stopped, suction in the line 12 fails, permitting the spring 15 to withdraw the lever 14 and the piston element 13 to the position where valve 10 again resumes the full choke position illustrated in the drawing.

In Figure 2 a modified form of suction device is illustrated and consists of an inflatable rubber member 18, one end of which is connected to the line 12 and the other end by a line 16 to the choke valve lever 14. This mechanism functions 10o precisely as that disclosed in connection with Fig. 1, the member 18 being collapsed when suction is availablein the line 12 thereby retarding lever 14 and opening the choke. When the suction fails in line 12 the member 18 assumes its normal expanded position whereby the lever 14 is replaced to the position wherein the butterfly valve 10 is in full choke position. The mechanism shown in Fig. 2 possesses ,the advantage of not requiring a coil spring such as the spring,

lfiillustrated in'Fig'. 1, since the member 18 automatically, by expanding, returns the valve operating lever 14 to the choke position.

In both figures 1 and 2 are shown regulating valves 19 which provide for leakage in the-suction cylinder 11 in' Fig. 1 and the suction line 12 in Fig. 2 for the purpose of regulating the speed of operation of the piston 13, as in Fig. 1 and the e1ement'18 in Fig. 2. By means of these regulating valves, the speed of operating the choke valve can be regulated so that in the winter time the choke will be opened more slowly when conditions are adverse to the rapid starting of the engine, and in summer time the choke operating mechanism can be adjusted to open the choke very quickly after the engine cranks.

In the modification shown in Fig. 3, the valve operating link '16 is provided with an armature 20 that is actuated by a solenoid 21 the winding of which has its terminals 22. and 23 connected to the generator of the engine. In operation after the engine cranks, the armature 20 is brought into engagement with magnet 21 and the latter being energized by the generator will hold link 16 and its attached choke valve 10 in open position as long as the engine is operating. This construction provides against the choke valve 10 closing upon a failure of suction in line 12.

In Fig. 4 the choke regulator is shown connected to the throttle control of the carbureter 5 control is set to maximum feed of gas to the engine.

When the engine is operating at high speed the suction in the intake manifold 4 is a minimum and by the engagement of lever 26 with the stop 27 the choke is held open independently of the suction.

It is evident from'the foregoing description of this invention that choke regulating means as provided for therein provides simple and expedient means for automatically choking the carbureter in starting the engine and to open its air intakeafter the engine is in operation.

Although several embodiments oi the invention have been herein illustrated and described, it will be obvious to those skilled in the art that various modifications may be made in the details of construction without departing from the principles herein set forth.

I- claim:

1. A choking device-for carburetors comprising a casing having an air inlet and being in connection with and forming a continuation of the carburetercasing, a choker valve in said first casing, a vacuum chamber in communication with the intake manifold of an engine, and a piston in said vacuum chamber and connected with the choker valve, whereby upon creating a vacuum the choker valve opens, said carbureter including a throttle valve controlling the outlet of said' carbureter, and means operatively connecting the throttle valve and the choker valve for control of the latter by the former.

2. The combination with a carbureter including a casing having an air inlet, of a choker valve in said casing, a vacuum chamber in communication with the intake manifold of an engine, a piston in said vacuum chamber and connected with the choker valve whereby upon creating a vacuum, the choker valve opens, said carbureter including a throttle valve controlling the outlet of said carbureter case, and means operatively connect- '1 

